Apparatus and method for treating a neuromuscular defect

ABSTRACT

A method is provided for treating a neuromuscular defect in a subject. One step of the method includes locating a target nerve. After locating the target nerve, a treatment probe is provided. The treatment probe includes an elongated body member having a proximal end portion and a distal end portion. The distal end portion includes an energy delivery mechanism for stimulating or ablating the target nerve, a monitoring mechanism, and a fluid aspiration/delivery mechanism. Next, the target nerve is verified as an appropriate target for ablation by stimulating and then monitoring the target nerve via the energy delivery mechanism and the monitoring mechanism, respectively. After verifying the target nerve, a tumescent fluid is injected into the tissue surrounding the target nerve. An electric current is then delivered to the energy delivery mechanism to substantially ablate the target nerve.

RELATED APPLICATION

This application claims priority from U.S. Provisional PatentApplication Ser. No. 61/089,015, filed Aug. 14, 2008, the subject matterof which is incorporated hereby incorporated by reference in itsentirety.

TECHNICAL FIELD

The present invention relates generally to an apparatus and method forneuromodulation, and more particularly to an apparatus and method forinterrupting nerve conduction through a target nerve to treat aneuromuscular defect.

BACKGROUND OF THE INVENTION

The human nervous system senses current information and conditions,which it then sends to various muscles to respond. As one example,consider the facial and neck nerves. These motor nerves control themuscles of facial expression and, thus, an individual's outwardmanifestations of well being and emotion. Neuromuscular defects candisrupt this information exchange and lead to undesired muscleresponses.

The involuntary contraction of facial or neck muscles (also known asdystonias) can distort an individual's facial expressions and garble theoutward appearance of the individual's feeling of well being andemotional state. For example, one type of dystonia, calledbelpharospasm, creates uncontrolled blinking and spasms in the eyelids.Another form of dystonia causes uncontrolled grimacing. Dystonias canalso affect neck muscles. For example, one form of dystonia, calledtorticollis, causes uncontrolled contraction of the neck muscles.

Apart from these hyperfunctional disorders, normal contraction of facialand neck muscles (e.g., by frowning or squinting) can form permanentfurrows or bands in the skin over time. These furrows or bands canpresent an aesthetically displeasing cosmetic appearance, and exposureto the sun can accelerate this undesired wrinkling process. As a morespecific example, the facial muscle corrugator supercilii draws theeyebrows downward and inward, producing vertical wrinkles of theforehead (also called glabellar frown lines). For this reason, thecorrugator supercilii is known as the frowning muscle and has beencalled the principal agent in the expression of suffering. Dystoniasaffecting the corrugator supercilii can lead to an unfortunate,continuous frowning expression, as well as the formation ofhyperfunctional frown lines and wrinkles in the face.

A surgical forehead lift procedure is one therapeutic modality oftenused to remove glabellar frown lines. The forehead lift requires a largeincision that extends from ear to ear over the top of the forehead. Thissurgically invasive procedure imposes the risk of bleeding and creates alarge skin flap that reduces blood supply to the skin. Numbness ofsensory nerves in the face, such as the supraorbital nerve can alsoresult.

A less invasive therapeutic modality is the administration ofinvertebrate exotoxins. For example, injection of the serotype A of theBotulinum toxin produces a flaccid paralysis of the corrugatorsupercilii. Tests have demonstrated that Botulinum toxin A may beadministered into the musculature of the face without toxic effect toproduce localized muscle relaxation for a period of about six months.The desired removal of hyperfunctional frowning lines is temporary, andrepeated treatments are needed about every 3 to 6 months.

Another form of treatment, disclosed in U.S. Pat. No. 5,370,642 toKeller, uses laser energy to eliminate glabellar frown lines andforehead wrinkles. The laser energy is used to resect large sections ofthe corrugator supercilii (as well as other facial muscles) and therebyinactivate the muscles. Like the surgical forehead lift, numbness of thesupraorbital nerve and other sensory nerves in the face can result.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, a method is providedfor treating a neuromuscular defect in a subject. One step of the methodincludes locating a target nerve. After locating the target nerve, atreatment probe is provided. The treatment probe comprises an elongatedbody member having a proximal end portion and a distal end portion. Thedistal end portion includes an energy delivery mechanism for stimulatingor ablating the target nerve, a monitoring mechanism, and a fluidaspiration/delivery mechanism. Next, the target nerve is verified as anappropriate target for ablation by stimulating and then monitoring thetarget nerve via the energy delivery mechanism and the monitoringmechanism, respectively. After verifying the target nerve, a tumescentfluid is injected into the tissue surrounding the target nerve. Anelectric current is then delivered to the energy delivery mechanism tosubstantially ablate the target nerve.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the present invention will becomeapparent to those skilled in the art to which the present inventionrelates upon reading the following description with reference to theaccompanying drawings, in which:

FIG. 1 is a process flow diagram illustrating a method for treating aneuromuscular defect in a subject according to the present invention;

FIG. 2 is a schematic illustration of a subject's orbital region showinguncontrolled blinking or blepharospasm;

FIG. 3 is an anterior view of the right side of the face showing thesuperficial facial and neck muscles and the branches of the facialnerves that control the facial and neck muscles;

FIG. 4A is a perspective view of a treatment probe constructed inaccordance with the present invention;

FIG. 4B is an exploded perspective view showing a distal end portion ofthe treatment probe in FIG. 4A;

FIG. 5 is a perspective view showing the distal end portion of thetreatment probe in FIG. 4A being positioned about a target nerve;

FIG. 6 is a perspective view showing the treatment probe in FIG. 5 beingused to deliver a tumescent fluid to the tissue surrounding the targetnerve;

FIG. 7A is a perspective view showing a neuromuscular junction locatedbetween a target nerve and a muscle;

FIG. 7B is a perspective view showing the distal end portion of thetreatment probe in FIG. 4B being used to substantially ablate the targetnerve; and

FIG. 8 is a schematic illustration showing the subject in FIG. 2 afterbeing treated for blepharospasm by the present invention.

DETAILED DESCRIPTION

The present invention relates generally to an apparatus and method forneuromodulation, and more particularly to an apparatus and method forinterrupting nerve conduction through a target nerve to treat aneuromuscular defect. As representative of the present invention, FIG. 1illustrates a method 10 for treating a neuromuscular defect in asubject. Although the present invention is described primarily in termsof treating cosmetic conditions affecting the face and neck, such asinvoluntary contraction of facial or neck muscles or the appearance oflines and wrinkles in the face or neck, it should be appreciated thatother neuromuscular defects, such as headaches and neuromuscular paincan also be treated by the present invention.

Unless otherwise defined, all technical terms used herein have the samemeaning as commonly understood by one of ordinary skill in the art towhich the present invention pertains.

In the context of the present invention, the terms “modulate” or“modulating” can refer to causing a change in neuronal activity,chemistry, and/or metabolism. The change can refer to an increase,decrease, or even a change in a pattern of neuronal activity. The termsmay refer to either excitatory or inhibitory stimulation, or acombination thereof, and may be at least electrical, magnetic, thermal,ultrasonic, optical or chemical, or a combination of two or more ofthese. The terms “modulate” or “modulating” can also be used to refer toa masking, altering, or overriding of neuronal activity.

As used herein, the term “target nerve” can refer to any portion of ahuman (or other mammalian) nervous system that has been identified tobenefit from receiving electric current. Non-limiting examples of targetnerves can include the facial nerve and any one of its branches, such asthe temporal branch, the zygomatic branch, the buccal branch, themarginal mandibular branch, and the cervical branch. Other examples oftarget nerves are illustrated in FIG. 3 and described in more detailbelow.

As used herein, the term “substantially ablate” can refer to damagecaused to a target nerve that results in partial or complete nervoustissue or nerve cell necrosis. The term can also refer to nervous tissueor nerve cell damage that falls short of complete ablation, e.g., somelevel of agitation or damage that is imparted to the nervous tissue ornerve cell to inure a desired change in the cellular makeup and/orelectrical activity of the tissue/cell, rather than necrosis of thetissue/cell.

As used herein, the term “subject” can refer to any warm-bloodedorganism including, but not limited to, human beings, pigs, rats, mice,dogs, goats, sheep, horses, monkeys, apes, rabbits, cattle, etc.

FIG. 1 is a process flow diagram illustrating one aspect of the presentinvention. In FIG. 1, a method 10 is provided for treating aneuromuscular defect in a subject. At 12, one step of the method 10includes identifying a neuromuscular defect in a subject. Generally, theneuromuscular defect can include any disease, disorder, or conditionthat adversely affects both nervous elements (e.g., brain, spinal cord,peripheral nerve) and muscle (e.g., striated or smooth). Non-limitingexamples of neuromuscular defects can include cosmetic defects,neurological movement disorders, neuromuscular pain, and headaches.

Non-limiting examples of cosmetic defects can include frown lines, linesor wrinkles between the eyes 26 (FIG. 2), crow's feet, horizontal linesin the forehead and neck, wrinkles around the mouth and chin, skinfurrows, contractions in the face and neck, spasms in the face or neck,and neck bands.

Neurological movement disorders can include any neurological disease orcondition that affects the speed, fluency, quality, and/or ease ofmovement in a subject. For example, abnormal fluency or speed ofmovement (dyskinesia) may involve excessive or involuntary movement(hyperkinesia) or slowed or absent voluntary movement (hypokinesia).Examples of neurological movement disorders can include, but are notlimited to, dystonias, torticollis, bleharospasm, and uncontrolledgrimacing.

Non-limiting examples of neuromuscular pain can include myofascial pain,fibromyalgia, TMJ pain, carpal tunnel syndrome, pain associated withmuscular dystrophy, orofacial pain, chronic head and neck pain, and painassociated with herniated and/or bulging or ruptured vertebral discs.Myofascial pain can involve any one or combination of nerves that supplythe face or, alternatively, indirect (referred) pain from otherstructures in the head, e.g., blood vessels. Myofascial pain may berelated to headache (e.g., migraine), muscular syndromes, such as TMJ,and herpetic or rheumatic disease or injury.

Non-limiting examples of headaches can include migraines, tensionheadaches, cluster headaches, trigeminal neuralgia, secondary headaches,and miscellaneous-type headaches. Migraines can include intense anddisabling episodic headaches typically characterized by severe pain inone or both sides of the head. For example, migraines can includemigraine without aura, migraine with aura, and migraine with aura butwithout headache. Cluster headaches can include extremely painful anddebilitating headaches that occur in groups or clusters. For example,cluster headaches can include cluster-type headaches, histamineheadaches, histamine cephalalgia, Raedar's syndrome, and sphenopalatineneuralgia.

To identify the neuromuscular defect, a subject is monitored for one ormore observable clinical symptoms associated with a particularneuromuscular defect. As shown in FIG. 2, for example, a subjectsuffering from blepharospasm may exhibit involuntary and sustainedmuscle contractions of the muscles around the eyes 26. Alternatively,symptoms associated with a particular neuromuscular defect may not beclinically observable. In this case, the subject may be asked to reporthis or her symptom(s) associated with the particular neuromusculardefect. For example, the subject may report the sensation of facial orhead pain associated with a headache.

After the neuromuscular defect has been identified, a target nerve islocated at 14. Generally, the target nerve can include any portion of asubject's nervous system that has been identified to benefit fromreceiving electric current based on the identified neuromuscular defect.Examples of target nerves in the face of a subject, as well as themuscles innervated by the target nerves are illustrated in FIG. 3. Itshould be appreciated, however, that other target nerves, such as thoseof the peripheral nervous system may also be targeted by the method ofthe present invention.

Referring to FIG. 3, the facial nerve 30 is the motor nerve thatcontrols a significant portion of the muscles responsible for facialexpressions. The branches of the facial nerve 30 pass around and throughsuperficial facial and neck muscles to control the corrugator superciliimuscle 32, the procerus muscle 34, and the platysma myoides muscle 36,among many others. The facial nerve 30 is the seventh cranial nerve,which is part of the peripheral nervous system of the body. Disorders ordefects in facial nerve 30 function can cause various cosmetic defects,such as blepharospasm. Thus, the facial nerve 30 and/or one of itsbranches can be an appropriate target nerve for treating a subjectsuffering from blepharospasm.

The corrugator supercilii 32 is a small and narrow pyramidal muscle. Thecorrugator supercilii 32 is located at the inner extremity of theeyebrow beneath the orbicularis palpebrarum muscle 38. As FIG. 3 shows,the temporal branch 40 of the facial nerve 30 provides additional nervebranches 42 to the corrugator supercilii muscle 32. The corrugatorsupercilii muscle 32 is called the “frowning muscle” because it drawsthe eyebrows downward and inward, producing vertical wrinkles in theforehead and in the space between the eyebrows.

The procerus 34 is a small, pyramidal band of muscles located over thenasal bone between the eyebrows. The zygomatico-buccal branch (not shownin detail) of the facial nerve 30 supplies the procerus muscle 34. Theprocerus muscle 34 draws down the inner angle of the eyebrows andproduces transverse wrinkles over the bridge of the nose.

The platysma myoides 36 is a broad, thin plane of muscular fiberslocated immediately beneath the superficial fascia on each side of theneck. The cervical branch (not shown in detail) of the facial nerve 30supplies the platysma myoides muscle 36. The platysma myoides muscle 36produces a wrinkling of the surface of the skin of the neck, in anoblique direction, when the entire muscle is brought into action. Italso serves to draw down the lower lip and angle of the mouth on eachside.

A neuromuscular defect can lead to uncontrolled contraction of one ormore of the corrugator supercilii 32, the procerus 34, and the platysmamyoides 36 muscles. Uncontrolled contraction of the corrugatorsupercilii muscle 32 or the procerus muscle 34, for example, cancontinuously contract the brow, giving the outward appearance ofdispleasure or disapproval even in the absence of the correspondingemotional state. Likewise, uncontrolled contraction of the platysmamyoides muscle 36 (called torticollis) can lead to sudden neck movement.Repeated normal contraction of the platysma myoides muscles 36 can alsolead to the formation of aesthetically displeasing bands in the skinarea below the neck over time. Even without hyperfunctional dysfunction,normal contraction of these muscles can, over time, cause aestheticallydispleasing frown lines or furrows in the forehead or in the spacebetween the eyebrows. Additionally, exposure to the sun can acceleratethis wrinkling process.

At 14, a treatment probe 44 (FIG. 4A) is used to verify that the targetnerve is an appropriate target for ablation. As shown in FIG. 4A, thetreatment probe 44 comprises an elongated body member 46 having aproximal end portion 48 and a distal end portion 50. The distal endportion 50 includes an energy delivery mechanism 52 (FIG. 4B) fordelivering electric current to a target nerve. As shown in FIG. 4B, thedistal end portion 50 also includes a monitoring mechanism 54 formonitoring the electrical activity of a target nerve and a fluidaspiration/delivery mechanism 56.

The energy delivery mechanism 52 and the monitoring mechanism 54 can beincluded as part of a hollow post member 58 located at the distal endportion 50 of the treatment probe 44. The post member 58 can have adistal end portion 60, a proximal end portion 62, and a channel 64extending between the end portions. The proximal end portion 62 can beintegrally formed with the elongated body member 46. Although not shownin FIG. 4B, the distal end portion 60 of the post member 58 can includea sharpened tip for penetrating tissue.

The energy delivery mechanism 52 can comprise a cuff or ring-shapedelectrode 66 disposed on the distal end portion 60 of the post member58. The electrode 66 can be made of any electrically-conductivematerial, such as platinum or platinum-iridium. It will be appreciatedthat any number of electrodes 66 may be operably disposed on the postmember 58 and, further, that the electrode(s) can have any desiredshape, such as a rectangular or ovoid shape.

The monitoring mechanism 54 can comprise a sensor 68 operably disposedon the post member 58. As shown in FIG. 4B, the sensor 68 is locatedproximal to the energy delivery mechanism 52; however, it should beappreciated that the sensor may alternatively be located distal to theenergy delivery mechanism. The sensor 68 is capable of monitoring adesired metabolic parameter (e.g., electrical activity) associated witha nerve, nervous tissue, and/or muscle function. For example, themonitoring mechanism 54 can include at least one electromyographic (EMG)electrode capable of receiving a signal from a target nerve or muscletissue when the electrode is placed in contact with the target nerve ormuscle tissue. As explained in more detail below, the monitoringmechanism 54 can be used to verify that a target nerve is an appropriatetarget for ablation.

Referring again to FIG. 4B, the fluid aspiration/delivery mechanism 56comprises the channel 64 extending between the distal and proximal endportions 60 and 62 of the post member 58. The fluid aspiration/deliverymechanism 56 can be used to selectively deliver a fluid or solution to atarget nerve and/or the tissue surrounding the target nerve. Forexample, the fluid aspiration/delivery mechanism 56 can be used todeliver a tumescent fluid (described below) to the tissue surrounding atarget nerve. Additionally, the fluid aspiration/delivery mechanism 56can be used to aspirate or remove fluid from the tissue at (orsurrounding) a target nerve.

A power button 70 (FIG. 4A) is operably disposed on the elongated bodymember 46 of the treatment probe 44, and can be used to selectivelycontrol the energy delivery mechanism 52, the monitoring mechanism 54,and the fluid aspiration/delivery mechanism 56. For example, the powerbutton 70 can be used to control delivery of electric current to theenergy delivery mechanism 52. Electrical energy can be delivered via apower source (not shown), such as a battery contained within thetreatment probe 44. Alternatively, electrical energy can be deliveredvia a power source externally coupled to the treatment probe 44. Forexample, the power source can be electrically connected to the proximalend portion 48 of the treatment probe 44 using an insulated electricallead or wire (not shown). The power source can comprise any devicecapable of generating electrical energy, such as high frequencyultrasound, high energy radiowaves, high frequency electricalstimulation, and laser energy.

At 16, the distal end portion 50 of the treatment probe 44 is positionedat or near a target nerve. Any one or combination of approaches can beused to access the target nerve with the treatment probe 44. Forexample, the post member 58 can be inserted directly through the skinadjacent a target nerve or, alternatively, an incision 72 (FIG. 5) canbe made in the skin adjacent the target nerve. In a subject sufferingfrom blepharospasm, for example, an incision 72 can be made near theright corner of a subject's eye 26 using a scalpel (not shown). In thiscase, the incision 72 should be made so that a portion of the facialnerve 30 and/or one of its branches is sufficiently exposed tofacilitate accurate placement of the treatment probe 44.

Next, the distal end portion 50 of the treatment probe 44 is urgedthrough the incision 72 so that the distal end portion 60 of the postmember 58 is in electrical contact with the target nerve. By “electricalcontact” it is meant that when electric current is delivered to theenergy delivery mechanism 52, deplorization of at least one neuroncomprising the target nerve is elicited. As shown in FIG. 5, forexample, the distal end portion 50 of the treatment probe 44 can beinserted into the incision 72 so that the energy delivery mechanism 52is adjacent a portion of the facial nerve 30 and/or one of its branches.The position of the energy delivery mechanism 52 relative to the targetnerve can be adjusted using the monitoring mechanism 54 during placementof the treatment probe 44. For example, the position of the energydelivery mechanism 52 can be adjusted based on sensed electricalpatterns in the target nerve and/or tissue surrounding the target nerveusing EMG mapping.

Following placement of the treatment probe 44, a determination is madeas to whether the target nerve is appropriate for ablation at 18. Toverify whether the target nerve is appropriate for ablation, electriccurrent is delivered to the energy delivery mechanism 52. Electriccurrent can be delivered to the energy delivery mechanism 52continuously, periodically, episodically, or a combination thereof. Forexample, electric current can be delivered in a unipolar, bipolar,and/or multipolar sequence or, alternatively, via a sequential wave,charge-balanced biphasic square wave, sine wave, or any combinationthereof. Electric current can be delivered all at once or, where theenergy delivery mechanism 52 comprises two or more electrodes 66,electric current can be delivered to only one of the electrodes using acontroller (not shown) and/or known complex practice, such as currentsteering.

The particular voltage, current, and frequency delivered to the energydelivery mechanism 52 may be varied as needed. For example, electriccurrent can be delivered to the energy delivery mechanism 52 at aconstant voltage (e.g., at about 0.1 v to about 25 v), at a constantcurrent (e.g., at about 25 microampes to about 50 milliamps), at aconstant frequency (e.g., at about 5 Hz to about 10,000 Hz), and at aconstant pulse-width (e.g., at about 50 μsec to about 10,000 μsec).

Delivery of electric current to the energy delivery mechanism 52stimulates the target nerve, i.e., causes the target nerve to increasethe frequency of nerve impulses. Depending upon the anatomicalstructure(s) and/or other nerve pathways innervated by the target nerve,a measurable result indicative of the appropriate target nerve can bedetermined upon delivery of electric current. In a subject sufferingfrom headache, for example, the measurable result may include somedegree of pain relief. Alternatively, in a subject suffering fromblepharospasm, the measurable result may include a reduction inuncontrolled blinking. If an appropriate measurable result is notobserved upon delivery of electric current, the treatment probe 44 canbe re-positioned, electric current again delivered to the energydelivery mechanism 52, and a measurable result then observed.

At 20, an appropriate volume of a tumescent fluid is injected into thetissue surrounding the target nerve. The tumescent fluid is selectivelydelivered to the tissue surrounding the target nerve via the channel 64of the post member 58 (FIG. 6). The tumescent fluid can be stored in thetreatment probe 44 or, alternatively, supplied from an external fluidsource (not shown). The tumescent fluid can comprise any solutioncapable of protecting superficial tissue planes from inadvertent heatdamage and enhancing electro-mechanical condition during delivery ofelectric current to the target nerve. For example, the tumescent fluidcan comprise sterile water or an electrolyte solution (e.g., aphysiologically normal saline solution).

Depending upon the particular neuromuscular defect being treated, thetumescent fluid can also include at least one pharmacological agent.Non-limiting examples of pharmacological agents can include anestheticagents, such as lidocaine, marcaine, nesacaine, diprivan, novocaine,ketalar and xylocaine, vasoconstrictive agents, such as epinephrine,levarterenol, phenylephrine, athyladrianol and ephedrine,anti-inflammatory agents, such as free radical scavengers andanti-oxidants (e.g., superoxide dismutase, catalase, nitric oxide,mannitol, allopurinol, and dimethyl sulfoxide), NSAIDS (e.g., aspirin,acetaminophen, indomethacin and ibuprofen), steroidal agents (e.g.,glucocorticoids and hormones), calcium channel blockers (e.g.,nimodipine, nifedipine, verapamil and nicardipine), NMDA antagonists(e.g., magnesium sulfate and dextromethorphan), and neurotoxic agents,such as Botulinum toxin.

After an appropriate volume of tumescent fluid has been injected intothe tissue surrounding the target nerve, the target nerve can besubstantially ablated at 22. To substantially ablate the target nerve,the energy delivery mechanism 52 is positioned substantially adjacent aportion of the contractile chain comprising the target nerve. Thecontractile chain comprises nerve tissue (e.g., a neuron), aneuromuscular junction 74 (FIG. 7A) (which generally forms the interfacebetween nerves and muscles), muscle tissue, and connective tissue. Asshown in FIG. 7A, for example, the energy delivery mechanism 52 can bepositioned substantially adjacent a neuromuscular junction 74.

Muscular movement is generally controlled by stimulation of a nerve. Themotor unit of the neuromuscular system contains three components: motorneuron (spine), axon (spine to motor endplate), and innervated musclefibers (endplate to muscle). Each muscle receives one or more supplynerves, and the supply nerve generally enters deep into the musclesurface near its origin where the muscle is relatively immobile. Oftentimes, blood vessels can accompany the nerve to enter the muscle at theneurovascular hilum. Each nerve contains motor and sensory fibers, motorendplates, vascular smooth muscle cells, and various sensory endings andendings in fascia. When the nerve enters the muscle, it breaks off intoa plexus running into the various layers of muscle epimysium, perimysiumand endomysium, each terminating in several branches joining a musclefiber at the motor endplate.

Substantially ablating one or more of these tissues may be sufficient totemporarily or permanently inhibit muscle contraction. Substantiallyablating a target nerve may interrupt or disable nerve impulses bydisrupting conductivity. Disruptions in nerve conductivity may be causedby eliminating or decreasing charge differences across plasma membranes,either mechanically or chemically, destroying Schwann cells thatinsulate the axonal processes, repeated injury/healing cycles timed tolimited capacity for neuron regeneration, or a combination thereof.

The energy delivery mechanism 52 can be brought into direct or indirectcontact with the target nerve. By “direct” it is meant that the energydelivery mechanism 52 is brought into physical contact with the targetnerve. By “indirect” it is meant that the energy delivery mechanism 52is positioned about the target nerve without directly contacting thetarget nerve, such that delivery of electric current to the energydelivery mechanism can modulate activity of the target nerve. Regardlessof the specific component of the contractile chain which issubstantially ablated, delivery of electric current to the target nervecan inhibit contraction of a muscle that would otherwise form or causethe neuromuscular defect.

Substantial ablation of the target nerve is accomplished when electriccurrent is delivered to the energy delivery mechanism 52 via the powerdelivery source. The parameters for delivery of electric current to theenergy delivery mechanism 52 can be identical or similar to theparameters described above. For example, electric current can bedelivered to the energy delivery mechanism 52 at a constant voltage(e.g., at about 0.1 v to about 25 v), at a constant current (e.g., atabout 25 microampes to about 50 milliamps), at a constant frequency(e.g., at about 5 Hz to about 10,000 Hz), and at a constant pulse-width(e.g., at about 50 μsec to about 10,000 μsec).

As shown in FIG. 7B, delivery of electric current to the energy deliverymechanism 52 can substantially ablate a neuromuscular junction 74comprising an end of a facial nerve 30 (or branch thereof) and theorbicularis palpebrarum muscle 38, for example. Such ablation may resultin a short-term, long-term, or permanent inactivation of the muscle.Other long-lasting or permanent treatments may involve inducingapoptosis to remodel the tissue behavior with long-term changes in thecellular life and/or proliferation cycles.

Specific ablative approaches used to change the function of a nerve andits corresponding muscle(s) in a desired way, or for a desired time, maybe induced by appropriate delivery of electric current to the energydelivery mechanism 52. Alternative ablative approaches that may beshorter in effect can include, for example, stunning of one or morecomponents of contractile chain or inactivating one or more of thecomponents. Ablative approaches that effectively block the release of,or response to, chemicals (e.g., neurotransmitters) along thecontractile chain may also be sufficient to inhibit (e.g., temporarilyor permanently) muscular contraction in response to signals transmittedalong the neural pathways.

After substantially ablating the target nerve, the subject can bere-assessed to determine if the method 10 was effective in treating theneuromuscular defect. In a subject suffering from blepharospasm, forexample, a medical practitioner or other health care professional canobserve the subject for uncontrolled blinking. Depending upon theobserved result, the method 10 can be repeated at 24. If the subjectexhibits normal blinking, for example, no additional treatment may beneeded. Where no additional treatment is needed, the incision 72 orentry point used to access the target nerve can be sutured or bandagedand the method 10 completed.

Although not illustrated in FIGS. 1-8, it should be appreciated that themethod 10 can be targeted to any one or combination of the nerves ormuscles identified in FIG. 3 to treat a variety of cosmetic defectsother than blepharospasm. For example, the method 10 may be directedtowards one or more of the levator palpebrae superioris, the frontalis,the levator labii, the corrugator supercilii 32, the zygomaticus minor,the zygomaticus major, the buccinator, and/or the temporalis. Treatmentstargeting contraction of the oticularis may help decrease crow's feetwrinkles, while treatments altering the function of the frontalis mayalleviate wrinkles. Additionally, wrinkles of the chin may be mitigatedby treatment of the mentali, and neck wrinkles may be improved bytreatment of the platysm 36.

Other examples of muscles whose innervating nerve(s) may besubstantially ablated to alleviate a cosmetic defect (or defects) caninclude the glabellar and procerus complex, the nasalis, the depressoranguli oris, the quadratus labii superioris and inferioris, thezygomaticus, the maxillae, the frontalis pars medialis, the frontalispars lateralis, the levator palpebrae superioris, the orbicularis oculipars orbitalis, the orbicularis oculi pars palpebralis, the levatorlabii superioris alaquae nasi, the levator labii superioris, thezygomaticus minor, the zygomaticus major, the levator anguli oris(a.k.a. caninus), the depressor anguli oris (a.k.a. triangularis), thedepressor labii inferioris, the mentalis, the incisivii labiisuperioris, the incisivii labii inferioris, the risorius, the masseter,the internal pterygoid, the digastric, the maxillae, and the quadratuslabii superioris and inferioris. Contraction of these and/or othermuscles may be inhibited by targeting associated nervous tissue(s),connective tissue(s), nerve/muscle interface(s), blood supply, or acombination thereof.

From the above description of the invention, those skilled in the artwill perceive improvements, changes and modifications. Suchimprovements, changes, and modifications are within the skill of the artand are intended to be covered by the appended claims.

1. A method for treating a neuromuscular defect in a subject, saidmethod comprising the steps of: locating a target nerve; providing atreatment probe, the treatment probe comprising an elongated body memberhaving a proximal end portion and a distal end portion, the distal endportion including an energy delivery mechanism for stimulating orablating the target nerve, a monitoring mechanism, and a fluidaspiration and delivery mechanism; verifying that the target nerve is anappropriate target for ablation by stimulating and then monitoring thetarget nerve via the energy delivery mechanism and the monitoringmechanism, respectively; injecting a tumescent fluid into the tissuesurrounding the target nerve; and delivering an electric current to theenergy delivery mechanism to substantially ablate the target nerve;wherein the neuromuscular defect is selected from the group consistingof cosmetic defects, neuromuscular pain and headaches.
 2. (canceled) 3.The method of claim 1, wherein the cosmetic defect is selected from thegroup consisting of skin furrows, frowning wrinkles, contractions,spasms, and neck bands.
 4. (canceled)
 5. The method of claim 1, whereinsaid step of locating a target nerve includes monitoring electricalactivity of the target nerve via the monitoring mechanism.
 6. The methodof claim 5, wherein electromyographic monitoring is used to monitor theelectrical activity of the target nerve.
 7. The method of claim 1,wherein said step verifying that the target nerve is an appropriatetarget for ablation further comprises the steps of: applying astimulation current to the target nerve via the energy deliverymechanism; and monitoring the subject for measurable result indicativeof the appropriate target nerve.
 8. The method of claim 7, wherein themeasurable result indicative of the appropriate target nerve is at leastone of an observable clinical result, an electromyographic signal orpattern, and a change in pain perception.
 9. The method of claim 1,wherein said step of injecting a tumescent fluid into the tissuesurrounding the target nerve further includes injecting apharmacological agent into the tissue surrounding the target nerve. 10.The method of claim 9, wherein the pharmacological agent is selectedfrom the group consisting of an anesthetic agent, an anti-inflammatoryagent, an electrolyte solution, and a neurotoxic agent.
 11. The methodof claim 10, wherein the neurotoxic agent comprises Botulinum toxin. 12.The method of claim 1, wherein said step of injecting a tumescent fluidinto the tissue surrounding the target nerve protects superficial tissueplanes from inadvertent heat damage and enhances electro-mechanicalconduction during delivery of electric current to the target nerve. 13.The method of claim 1, wherein said step of injecting a tumescent fluidinto the tissue surrounding the target nerve anesthetizes at least aportion of the tissue.
 14. The method of claim 1, wherein said steps ofproviding a treatment probe and verifying that the target nerve is anappropriate target for ablation are repeated until the treatment probeis correctly positioned.
 15. The method of claim 1, wherein said methodis repeated until the neuromuscular defect is treated.
 16. The method ofclaim 1, wherein the energy delivery mechanism is powered by at leastone of high frequency ultrasound, high energy radiowaves, high frequencyelectrical stimulation, and laser energy.
 17. The method of claim 1,wherein said step of injecting a tumescent fluid into the tissuesurrounding the target nerve protects superficial tissue planes frominadvertent heat damage and enhances electro-mechanical conductionduring delivery of electric current to the target nerve.
 18. The methodof claim 1, wherein the treatment probe further includes a power buttondisposed on the elongated member.
 19. The method of claim 1, wherein thetumescent fluid is stored in the elongate body member of the treatmentprobe.
 20. The method of claim 1, wherein said step of delivering anelectric current further includes substantially ablating a neuromuscularjunction.